- NGC 7331, also known as Caldwell 30, is an unbarred spiral galaxy about 40 million light-years (12 Mpc) away in the constellation Pegasus. It was discovered by William Herschel in 1784. NGC 7331 is the brightest galaxy in the field of a visual grouping known as the NGC 7331 Group of galaxies. In fact, the other members of the group, NGC 7335, 7336, 7337 and 7340, lie far in the background at distances of approximately 300–350 million light years.[
- Pegasus (constellation) (Wikipedia)
Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and is one of the 88 constellations recognised today.
- Double star (Wikipedia)
In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes.